89 T-Bird Premium Sound Update

After getting some time to look this over a little I have more info on the problem. 1st, the HU currently in the car is a 1994 model. 2nd The car will produce sound with a 1989 HU, but the only one around doesn't do anything but put out static and a little music. (It's in sad shape, plus would prefer to use the 94 HU since it has better features). 3rd, I located some info on the fact that the 94 HU's amp trigger is 6 volt, and the 89 HU trigger is 12 volt. I spliced the trigger wire to a 12 volt wire and can get music, but at a very low volume level. (The 89 HU puts out plenty of volume). The amp must be ok since it puts out volume with the 89 HU. The wiring for the 94 HU must have more differences than just the amp trigger. Does anyone know of a way to hook up the 1994 HU in this 1989 car?  Thanks.

thats the craziest stock hu prob ive heard of.yup

lets see here the new hu triggers the amp at 6 volts and the old one at 12. so you got the right idea by splicing into a 12 volt source. but you get volume at low levels. does turning up the stereo help? lol. well since im going off of standard trial and error what i would do next is get a line converter and use it to turn the gain up on the factory amp setting. if that dosent work id look on ebay or something for a stereo that will work but that is still newer.yup

I have a line converter and Rockford Fosgate amp that I could easily hook up to this system in place of the factory amp. I have thought about doing that, but I would like to keep it stock if possible (plus the amp is only 2-channel and a bit older, so I would just have R and L control instead of F and R. As a last resort I have an Alpine HU and CD changer that will go into this car.) The 94 HU has two "screws" set into the side that MIGHT be gain controls, but I don't know for sure what they are and don't want to mess with them until I do. (They are not labeled in any way.) What I don't get for sure is that in looking around at wiring diagrams I find 1988 ones that have the amp trigger as #8, the antenna power as #7, and the (big RED) ground as number #6. (These could also be #'s 1, 2, and 3 depending on which end of the connector you count from. And yes, the factory did use Red for the system ground. I checked into that.) On 94 diagrams they have #8 as amp trigger, #7 as open, and #6 as amp ground. Ok that makes sense, it is basicly the same so the newer HU should work when the trigger is hooked to 12 volts. BUT on my 1989 it is #8 amp trigger, #7 (RED) ground, and #6 ???. This set-up works with a bona-fide 1989 HU, so it must be right (not changed by someone, somewhere.) but what is this doing with the 94 HU? (If the amp ground is in the wrong place that might be why no volume, but would I get any sound at all? Also, how come something doesn't short out if the ground is not where it should be on the 94 HU? If it is just the amp ground, and not the sys ground I can see the HU working, but still it's hooking up a ground to a wire that should be an "open" so what happens there?) I am going to try to splice into that ground and ground it elsewhere and see what happens. (When I get time.) Any thoughts before I do?   Thanks.

hope this helps http://www.installdoctor.com/Harnesses/Ford-Wiring.pdf yup

Well I pulled the stock set up and I'm putting in the Alpine. I hooked everything up to make sure it works, and then went to install the HU in the dash. (That's a fun job all by itself). Anyway, after getting it in there, with all the wiring and the LOC, etc. I go to check it out again and after listening to a CD for about 2 minutes the CD changer dies. Then, after I pull the HU out (Another fun job. Ford did not make this car to install a non-factory unit.) and check everything for a bad connection, the HU dies. By now I'm ticked at this whole project. (Since I've been messing with it for most of Fri. and Sat.)  I couldn't get the HU to do anything so I pulled it out and figured I'd check it right at the battery since maybe I lost power at the connector. I hook it up direct to the battery, nothing. I think this doesn't make sense so I go to start the car, the battery is stone dead. (The amp must have killed it. I didn't start the car for 2 days and spent quite a few hours with the ignition on and the doors open.) Anyway, I charged it up and re-checked everything and all works, but I still have to install everything. I guess now I know why I'm not and audio freak. How much power does an amp pull? (It's an older Rockford Fosgate. I can't tell the model # or details since I can't locate a number, but it looks to be a mid-90's Punch series. ) Also, I was on the right track with thinking it was the stock HU to amp wiring. I hooked the LOC to the stock HU and to the R/F amp (since theres no way to hook up RCA inputs to the stock amp) and it worked. I just figured since I had to use the R/F amp I'd just use the whole aftermarket set up. Sounds good. (Seriously hurts the value of the car though. A near mint T-Bird too.)